From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5C92CCA489 for ; Tue, 26 Jul 2022 06:43:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232278AbiGZGnJ (ORCPT ); Tue, 26 Jul 2022 02:43:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230464AbiGZGnH (ORCPT ); Tue, 26 Jul 2022 02:43:07 -0400 Received: from mailgw01.mediatek.com (unknown [60.244.123.138]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB19F1B79B; Mon, 25 Jul 2022 23:43:05 -0700 (PDT) X-UUID: ed2d3175cf0546bf91be188b386b5082-20220726 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.8,REQID:1323187d-3f50-4f41-8e52-a0f8b96b44e4,OB:0,LO B:0,IP:0,URL:0,TC:0,Content:0,EDM:0,RT:0,SF:0,FILE:0,RULE:Release_Ham,ACTI ON:release,TS:0 X-CID-META: VersionHash:0f94e32,CLOUDID:a77182b3-06d2-48ef-b2dd-540836705165,C OID:IGNORED,Recheck:0,SF:nil,TC:nil,Content:0,EDM:-3,IP:nil,URL:0,File:nil ,QS:nil,BEC:nil,COL:0 X-UUID: ed2d3175cf0546bf91be188b386b5082-20220726 Received: from mtkexhb01.mediatek.inc [(172.21.101.102)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1604846816; Tue, 26 Jul 2022 14:42:59 +0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs10n2.mediatek.inc (172.21.101.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.792.3; Tue, 26 Jul 2022 14:42:58 +0800 Received: from mtksdccf07 (172.21.84.99) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 26 Jul 2022 14:42:58 +0800 Message-ID: <9c5b85034ec77be80d771ce3a17260453f007728.camel@mediatek.com> Subject: Re: [PATCH v14 05/10] drm/mediatek: Add MT8195 Embedded DisplayPort driver From: Rex-BC Chen To: CK Hu , "chunkuang.hu@kernel.org" , "p.zabel@pengutronix.de" , "daniel@ffwll.ch" , "robh+dt@kernel.org" , "krzysztof.kozlowski+dt@linaro.org" , "mripard@kernel.org" , "tzimmermann@suse.de" , "matthias.bgg@gmail.com" , "deller@gmx.de" , "airlied@linux.ie" CC: "msp@baylibre.com" , "granquet@baylibre.com" , Jitao Shi =?UTF-8?Q?=28=E7=9F=B3=E8=AE=B0=E6=B6=9B=29?= , "wenst@chromium.org" , "angelogioacchino.delregno@collabora.com" , LiangXu Xu =?UTF-8?Q?=28=E5=BE=90=E4=BA=AE=29?= , "dri-devel@lists.freedesktop.org" , "linux-mediatek@lists.infradead.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-fbdev@vger.kernel.org" , Project_Global_Chrome_Upstream_Group Date: Tue, 26 Jul 2022 14:42:58 +0800 In-Reply-To: <378f904a445e90d65048ed07a1a55fd8c633f934.camel@mediatek.com> References: <20220712111223.13080-1-rex-bc.chen@mediatek.com> <20220712111223.13080-6-rex-bc.chen@mediatek.com> <378f904a445e90d65048ed07a1a55fd8c633f934.camel@mediatek.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2022-07-25 at 17:16 +0800, CK Hu wrote: > Hi, Bo-Chen: > > On Tue, 2022-07-12 at 19:12 +0800, Bo-Chen Chen wrote: > > From: Markus Schneider-Pargmann > > > > This patch adds a embedded displayport driver for the MediaTek > > mt8195 > > SoC. > > > > It supports the MT8195, the embedded DisplayPort units. It offers > > DisplayPort 1.4 with up to 4 lanes. > > > > The driver creates a child device for the phy. The child device > > will > > never exist without the parent being active. As they are sharing a > > register range, the parent passes a regmap pointer to the child so > > that > > both can work with the same register range. The phy driver sets > > device > > data that is read by the parent to get the phy device that can be > > used > > to control the phy properties. > > > > This driver is based on an initial version by > > Jitao shi > > > > Signed-off-by: Markus Schneider-Pargmann > > Signed-off-by: Guillaume Ranquet > > Signed-off-by: Bo-Chen Chen > > --- > > [snip] > > > + > > +static int mtk_dp_training(struct mtk_dp *mtk_dp) > > +{ > > + short max_retry = 50; > > + int ret; > > + > > + do { > > + ret = mtk_dp_train_start(mtk_dp); > > + if (!ret) > > + break; > > + else if (ret != -EAGAIN) > > + return ret; > > + } while (--max_retry); > > mtk_dp_train_start() would never return -EAGAIN, so drop this while > loop. > > Regards, > CK > Hello CK, the function will not return -EAGAIN, but we still want to retry 50 times if mtk_dp_train_start() is failed. If we retry 50 times and it is still failed. We can confirm there are some issues for the device. I will remove the else if of -EAGAIN and keep th while loop. BRs, Bo-Chen > > > > + if (!max_retry) > > + return -ETIMEDOUT; > > + > > + ret = mtk_dp_video_config(mtk_dp); > > + if (ret) > > + return ret; > > + mtk_dp_video_enable(mtk_dp, true); > > + > > + return 0; > > +} > > + > >